1. Field of the Invention
The present invention relates to a projection system, and more particularly, to a projection system and a cooling system thereof which smoothly cools a reflecting-type projection system forming an image with an LCOS panel. Still more particularly, it relates to a projection system and a cooling system thereof which smoothly cools an optical engine generating high heat in the projection system.
2. Description of the Background Art
Unlike a general liquid crystal display, a liquid crystal on silicon (hereinafter, referred to as “LCOS”) that is a kind of a reflecting-type liquid crystal display forms a liquid crystal cell on a semiconductor substrate and can realize a large screen having a high definition of a XGA grade or more in a small size of about one inch by arranging switching circuits and elements of each pixel in high integration.
For these reasons, the LCOS panel has been attracted as a display device of the projection system and technical development and commercialization of the LCOS panel and a projection display system using the LCOS panel have been actively progressed.
In order to embody a full color screen, the projection system uses a three panel type which converts white color light to RGB three color light, has three LCOS panels corresponding to the R, G, B light to compose R, G, B images embodied by each LCOS panel in a color image, and projects the composed image to a screen.
Such general LCOS projection system includes an illumination unit for projecting light, a composition unit for composing RGB three images displayed in the LCOS panel in an image after projecting light, a projecting lens for projecting light composed in the composition unit, and a screen for displaying light projected from the projecting lens to an image.
Specifically, all of the illumination unit, the composition unit, and the projecting lens are called as an optical engine and the optical engine is highly heated by an illuminating light of the lamp. Accordingly, a suitable cooling system should be provided to cool such high heat. However, when outside air is injected to cool, it is important to allow foreign substance with cooling air not to be injected. If high heat is not cooled, many films provided in the illumination unit and the LCOS panel provided in the composition unit are may be oxidized and thus the projection system may be not normally operated.